Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038220 (status epilepticus)
 7,272 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The use of magnesium sulfate (MgSO4) as an anticonvulsant is controversial. Status epilepticus was induced in 0.5% halothane-anesthetized Wistar rats with a threshold (90 mg/kg) or suprathreshold (200 mg/kg) dose of intravenous (i.v.) pentylenetetrazol (PTZ) under stereotactic hippocampal depth electrode monitoring. Fifteen minutes after seizure induction, the maximum hemodynamically tolerated dose of MgSO4 (10 mg/kg/min in 22 min) was administered i.v. MgSO4 was ineffective in altering seizure discharge. A subgroup of nine animals received hypertonic mannitol before MgSO4 to open the blood-brain barrier (BBB) to facilitate Mg2+ CNS penetration. Again MgSO4 was ineffective in attenuating epileptic activity. These results support the contention that MgSO4 is not an effective treatment for status epilepticus. We hypothesize that because Mg2+ blocks Ca2+ influx into the neuron through the N-methyl-D-aspartate (NMDA) receptor-operated calcium channel in a voltage-dependent manner it would be ineffective in neurons that are continuously depolarizing as in status epilepticus.
 ...
PMID:Effects of magnesium sulfate on pentylenetetrazol-induced status epilepticus. 183 Nov 20

Seizures in pregnancy pose risks for both the mother and the fetus and must be managed aggressively. Antiepileptic drugs have some teratogenic potential, but the risks are not as profound as reported in earlier literature. There is definitely less risk to the fetus from anticonvulsant exposure than from uncontrolled seizures. The evaluation of a pregnant woman with new-onset seizures is the same as for the nonpregnant patient, including head computed tomography with appropriate abdominal shielding. Status epilepticus management is based on IV benzodiazepines, phenytoin, or phenobarbital. Good fetal outcome is dependent on rapid seizure control. Management of eclampsia is controversial. There is little evidence that magnesium sulfate has anticonvulsant properties, and its use as such will probably decline steadily in the future. At present, it is reasonable to manage eclamptic seizures in the same way that status epilepticus is managed.
 ...
PMID:Emergency department approach to managing seizures in pregnancy. 195 21

An unsuccessful attempt to terminate myoclonic status epilepticus with elevation of serum magnesium levels is described. During 3 days, serum magnesium was increased from 1.5 mEq/L to 14.2 mEq/L by continuous i.v. infusion of 3-6 g/h of magnesium sulfate. Other anticonvulsants were maintained at nearly constant levels. Cerebrospinal fluid magnesium was 3.5 mEq/L during the infusion. Despite magnesium-related neuromuscular blockade and accompanying cessation of visible myoclonus, the electroencephalogram revealed ongoing blunted sharp-wave activity at the baseline frequency. Transient complications of the infusion included prolongation of the PR interval on the electrocardiogram, hypomotility of the gastrointestinal tract, and peripheral muscle flaccidity, all of which resolved within 24 h of return to normal serum magnesium levels. These results suggest that the therapeutic role of magnesium in myoclonic status epilepticus is limited.
 ...
PMID:Failure of high-dose intravenous magnesium sulfate to control myoclonic status epilepticus. 314 67

Specific biochemical hallmarks of apoptosis, namely internucleosomal DNA fragmentation and caspase-3 activation, appear in the aftermath of status epilepticus (SE). This led us to hypothesize that caspase-activated DNase (CAD) is involved in DNA fragmentation and apoptotic neuronal cell death following SE. The present study aimed to determine whether SE is associated with an activation of CAD, as reflected in the degradation of the CAD inhibitor, ICAD. SE was induced in adult male Sprague-Dawley rats by kainic acid (12 mg/kg i.p.) and seizures were terminated with diazepam after 2 h. At 24, 48, or 72 h after SE termination, protein levels of CAD and ICAD were measured by Western blotting (after sodium dodecyl sulfate-polyacrylamide gel electrophoresis) using specific antibodies. At 48 and 72 h after SE termination, ICAD protein levels significantly decreased (by more than 60%) in rhinal cortex and hippocampus as compared with those in the same tissue from animals not experiencing SE. No changes were detected in total CAD protein levels at any time point, resulting in an increase in the ratio of CAD to its inhibitor. The loss of ICAD following SE is indicative of a disinhibition of CAD, leading to DNA fragmentation. Consistent with this, we observed that the decrease in ICAD between 24 and 48 h was accompanied by a marked increase in DNA fragmentation. Our results support the proposal that CAD participates in caspase-3-mediated internucleosomal DNA fragmentation in the aftermath of SE.
 ...
PMID:Status epilepticus leads to the degradation of the endogenous inhibitor of caspase-activated DNase in rats. 1183 14

This study evaluated the effectiveness of fosphenytoin as a single or adjunctive anticonvulsant treatment for nerve agent-induced status epilepticus. Guinea pigs, implanted with cortical electroencephalographic (EEG) recording electrodes, were pretreated with pyridostigmine bromide (0.026 mg/kg, intramuscular (i.m.)) 30 min before challenge with 56 micrograms/kg, subcutaneous (s.c.), (2 x LD50) of the nerve agent soman. One min after soman, the animals were treated (i.m.) with 2 mg/kg atropine sulfate admixed with 25 mg/kg of the oxime 2-pralidoxime chloride, and the EEG was observed for seizure onset. When administered (intraperitoneal, i.p.) therapeutically 5 min after seizure onset, only the highest fosphenytoin dose (180 mg/kg) was capable of terminating seizure activity in 50% of the animals tested (3 of 6). When fosphenytoin (18-180 mg/kg) was administered as a pretreatment, i.p., 30 min before soman challenge, seizures were blocked or terminated in a dose-dependent fashion (ED50 = 61.8 mg/kg; 40.5-94.7 mg/kg = 95% confidence limits). Combinations of diazepam and fosphenytoin were also tested for effectiveness. No dose of fosphenytoin (18-56 mg/kg), given in conjunction with a fixed dose of diazepam (4.8 mg/kg, i.m.) 5 min after seizure onset, enhanced the anticonvulsant effect of diazepam. When fosphenytoin (18 or 32 mg/kg, i.p.) was given as a pretreatment and diazepam was given 5 min after seizure onset, the 32 mg/kg dose of fosphenytoin significantly reduced the time for seizure control. These studies show that fosphenytoin, either alone or in combination with diazepam, has little or no therapeutic anticonvulsant effectiveness for nerve agent-induced status epilepticus.
 ...
PMID:Effects of fosphenytoin on nerve agent-induced status epilepticus. 1503 46

Because magnesium has antiseizure effects in some animal models of epilepsy, and possible neuroprotective effects in some models of neuronal injury, we aimed to investigate its effects in the kainic acid (KA) model of status epilepticus (SE) in prepubescent rats. This age was chosen because it is a common age for onset of epilepsy and of SE in humans. Three groups of P35 rats were studied: Group I (MgKA) received magnesium sulfate MgSO4 (270 mg/kg then 27 mg/kg every 20 minutes for 5 hours) and 10 mg/kg KA. Group II (KA) received saline instead of MgSO4 and 10 mg/kg KA. Group III (control) received saline injections only. The dose we used has been shown previously to have anticonvulsant activity in another seizure model. Rats were recorded for their acute behavioral seizures directly after KA, and underwent the handling and Morris Water Maze (MWM) tests on P96-97 and P102-106 respectively. The MgKA and the KA groups did not differ in their acute seizures and both showed similar histologic lesions in CA3/CA4 and CA1 hippocampal subfields, and were more aggressive on the handling test than control rats. The MgKA group took more time to reach the platform in MWM than controls, while the KA group scores were intermediate between the two groups. Using the dose of 540 mg/kg MgSO4 and 54 mg/kg every 20 min showed the similar result of lack of protection against impairment in long-term memory. We conclude that (1) Magnesium did not manifest acute behavioral antiseizure effects in the KA P35 model of SE. (2) Magnesium did not prevent the tested long-term behavioral and histological consequences of SE in this model.
 ...
PMID:Effects of magnesium sulfate in kainic acid-induced status epilepticus. 1733 Mar 72

Soman poisoning is known to induce full-blown tonic-clonic seizures, status epilepticus (SE), seizure-related brain damage (SRBD) and lethality. Previous studies in guinea-pigs have shown that racemic ketamine (KET), with atropine sulfate (AS), is very effective in preventing death, stopping seizures and protecting sensitive brain areas when given up to 1h after a supra-lethal challenge of soman. The active ketamine isomer, S(+) ketamine (S-KET), is more potent than the racemic mixture and it also induces less side-effects. To confirm the efficacy of KET and to evaluate the potential of S-KET for delayed medical treatment of soman-induced SE, we studied different S-KET dose regimens using the same paradigm used with KET. Guinea-pigs received pyridostigmine (26 microg/kg, IM) 30min before soman (62 microg/kg, 2 LD(50), IM), followed by therapy consisting of atropine methyl nitrate (AMN) (4 mg/kg, IM) 1min following soman exposure. S-KET, with AS (10mg/kg), was then administered IM at different times after the onset of seizures, starting at 1h post-soman exposure. The protective efficacy of S-KET proved to be comparable to KET against lethality and SRBD, but at doses two to three times lower. As with KET, delaying treatment by 2h post-poisoning greatly reduced efficacy. Conditions that may have led to an increased S-KET brain concentration (increased doses or number of injections, adjunct treatment with the oxime HI-6) did not prove to be beneficial. In summary, these observations confirm that ketamine, either racemic or S-KET, in association with AS and possibly other drugs, could be highly effective in the delayed treatment of severe soman intoxication.
 ...
PMID:Protective effects of S+ ketamine and atropine against lethality and brain damage during soman-induced status epilepticus in guinea-pigs. 1740 39

Systemic application of the muscarinic agonist, pilocarpine, is commonly utilized to induce an acute status epilepticus that evolves into a chronic epileptic condition characterized by spontaneous seizures. Recent findings suggest that the status epilepticus induced by pilocarpine may be triggered by changes in the blood-brain barrier (BBB) permeability. We tested the role of the BBB in an acute pilocarpine model by using the in vitro model brain preparation and compared our finding with in vivo data. Arterial perfusion of the in vitro isolated guinea-pig brain with <1 mM pilocarpine did not cause epileptiform activity, but rather reduced synaptic transmission and induced steady fast (20-25 Hz) oscillatory activity in limbic cortices. These effects were reversibly blocked by co-perfusion of the muscarinic antagonist atropine sulfate (5 microM). Brain pilocarpine measurements in vivo and in vitro suggested modest BBB penetration. Pilocarpine induced epileptiform discharges only when perfused with compounds that enhance BBB permeability, such as bradykinin (n=2) or histamine (n=10). This pro-epileptic effect was abolished when the BBB-impermeable muscarinic antagonist atropine methyl bromide (5 microM) was co-perfused with histamine and pilocarpine. In the absence of BBB permeability enhancing drugs, pilocarpine induced epileptiform activity only after arterial perfusion at concentrations >10 mM. Ictal discharges correlated with a high intracerebral pilocarpine concentration measured by high pressure liquid chromatography. We propose that acute epileptiform discharges induced by pilocarpine treatment in the in vitro isolated brain preparation are mediated by a dose-dependent, atropine-sensitive muscarinic effect promoted by an increase in BBB permeability. Pilocarpine accumulation secondary to BBB permeability changes may contribute to in vivo ictogenesis in the pilocarpine epilepsy model.
 ...
PMID:Acute induction of epileptiform discharges by pilocarpine in the in vitro isolated guinea-pig brain requires enhancement of blood-brain barrier permeability. 1808 73

A 36-year-old primigravida with a history of temporal lobe epilepsy presented at 25 weeks of pregnancy with generalized tonic clonic seizures. The clinical picture was confused with eclampsia because of rising blood pressure and proteinuria. Clinical investigations, which included a lumbar puncture, were carried out to rule out an infective cause for the seizures. A computed tomography of the brain was performed for evidence of intracranial hemorrhage. The patient was intubated and ventilated in the intensive care unit. The labile blood pressure settled in 2 days, and the transient heavy proteinuria also resolved after 3 days. Eclampsia would have warranted operative delivery of the preterm fetus with the attendant problems of prematurity. Delivery would have been hazardous in such an acutely unwell patient. The management also would have required magnesium sulfate with its potential for toxicity. Transient proteinuria may occur in status epilepticus. The blood pressure can be labile during epileptic seizures and, in the absence of an intracranial hemorrhage, generally settles without treatment after control of the seizures. This case highlights the importance of differentiating eclampsia in a patient with known epilepsy that may also mask other disease entities such as intracranial hemorrhage, meningitis, or encephalopathy. We have also discussed the importance of various signs associated with eclampsia and their clinical significance. The differential diagnosis of seizures in pregnancy are broad as symptoms of the various disease entities including eclampsia, intracranial hemorrhage, status epilepticus, meningitis, stroke overlap creating a dilemma in an acute emergency. We present a case whereby the clinical picture of status epilepticus was confused with eclampsia because of the presence of a rising blood pressure and proteinuria.
 ...
PMID:Proteinuria in status epilepticus or eclampsia; a diagnostic dilemma. 1949 73

Novel therapeutics to overcome the toxic effects of organophosphorus (OP) chemical agents are needed due to the documented use of OPs in warfare (e.g. 1980-1988 Iran/Iraq war) and terrorism (e.g. 1995 Tokyo subway attacks). Standard OP exposure therapy in the United States consists of atropine sulfate (to block muscarinic receptors), the acetylcholinesterase (AChE) reactivator (oxime) pralidoxime chloride (2-PAM), and a benzodiazepine anticonvulsant to ameliorate seizures. A major disadvantage is that quaternary nitrogen charged oximes, including 2-PAM, do not cross the blood brain barrier (BBB) to treat brain AChE. Therefore, we have synthesized and evaluated pro-2-PAM (a lipid permeable 2-PAM derivative) that can enter the brain and reactivate CNS AChE, preventing seizures in guinea pigs after exposure to OPs. The protective effects of the pro-2-PAM after OP exposure were shown using (a) surgically implanted radiotelemetry probes for electroencephalogram (EEG), (b) neurohistopathology of brain, (c) cholinesterase activities in the PNS and CNS, and (d) survivability. The PNS oxime 2-PAM was ineffective at reducing seizures/status epilepticus (SE) in diisopropylfluorophosphate (DFP)-exposed animals. In contrast, pro-2-PAM significantly suppressed and then eliminated seizure activity. In OP-exposed guinea pigs, there was a significant reduction in neurological damage with pro-2-PAM but not 2-PAM. Distinct regional areas of the brains showed significantly higher AChE activity 1.5h after OP exposure in pro-2-PAM treated animals compared to the 2-PAM treated ones. However, blood and diaphragm showed similar AChE activities in animals treated with either oxime, as both 2-PAM and pro-2-PAM are PNS active oximes. In conclusion, pro-2-PAM can cross the BBB, is rapidly metabolized inside the brain to 2-PAM, and protects against OP-induced SE through restoration of brain AChE activity. Pro-2-PAM represents the first non-invasive means of administering a CNS therapeutic for the deleterious effects of OP poisoning by reactivating CNS AChE.
 ...
PMID:Pro-2-PAM therapy for central and peripheral cholinesterases. 2015 30


1 2 3 4 Next >>